{Collins} KWM2 - Air Force T.O. Change - was wondering if commercial manual showed change

Hi All,

I hope I am not wasting your time here.

In the early 1970's,  I worked  as a Ground Radio Tech at Tinker AFB. I had
made a discovery which became important enough to change the Technical
Orders for testing the S-line transmitting equipment. I was wondering if
this filters down to commercial manuals.

We were responsible for keeping over 100 sets of KWM-2A's, 30L-1's and a
handful of 30S-1's The power output on a number of units would never meet
specs. We went through the standard PA tune and Load into a dummy load with
a wattmeter for a specific number of milliamps on the front panel meter. We
were supposed to get full power output with this setup.

I cannot begin to tell you how many perfectly good 6146's which were thrown
into the trash as they would never seem to make the specified power output.
Whenever something went wrong, most techs would blame "Faulty PA tubes" as
the issue (with these PA's having no previous hours on them other than

I  was "loaned" to the KWM-2A group from another section to help figure why
the worst offenders would not work. I decided to take one of these units
that would never load up correctly, and ignore the front panel
meter current reading, and load to see what I could get out of these. I
found the units had the capability to put out 1.5X as much power as the
T.O. required. I removed the meter and tested against an accurate current
meter. I found the KWM2 meter was way off (too high). I wrote it up to
headquarters, and they changed the manual to check calibration of the front
panel meter during quarterly checks. No more bad units after that.

After that point, I checked the meters of 30L-1's and the occasional
30S-1's that would never meet specs. Simple front panel meter
issues had techs throwing out hundreds of 6146's and 811A's (Not many
4CX1000's were tossed as we had inly a few units).

These units (except for the 30S-1's) were kept in Samsonite suitcases and
jarred around a bit, so they would need "tuning up" ( I hated the
neutralization process - got bit a few times).

However, I digress,

Did this process ever make it's way back into Collins documentation to test
the meters in the S-Line equipment?  They seemed susceptible to damage.


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